How to drive a 10-speed transmission
A 10-speed transmission is one of the most common and simplest transmissions for shifting tractor-trailer trucks. Like the manual transmission in a vehicle, the shift pattern on most large trucks is designed in a standard “H” format. The main difference is that on large trucks there is a lower range and an upper or high range. Transmissions carrying more than 10 speeds also have an additional splitter. Driving a semi forces the driver to downshift, which is not as common when driving a car or other smaller vehicle with a manual transmission.
Let the engine idle long enough for the vehicle’s air pressure to reach its range. Make sure the selector knob is in the low range gear pattern. The button should be in the down position to be in the low range.
Depress the clutch and engage second gear. The lower gear and first gear are generally not required unless the truck is stopped on an incline or is carrying a heavy load. Likewise, the truck does not require the driver to press the accelerator to put the truck in forward motion. Release pressure on the clutch slowly until the truck begins to move. Slowly accelerate while watching the tachometer.
Shift to the next gear, once the rotation per minute (rpm) is around 1,200 to 1,300. To shift gears more effectively, depress the clutch just enough to disengage the transmission and move the shift lever out of gear and release the clutch. Depress the clutch again as the revolutions per minute decrease and gently move the shift lever into the next gear position. This method of shifting is known as double clutching and will help increase the long-term life of your transmission.
Repeat steps 1 through 3 through the low range gears. Before shifting into the first gear of the high range, flip the selector knob up to preset it for the next gear change.
Double-clutch and place the gear lever in the next gear. The purpose of the high speed range selector is to allow the driver to continue to reuse the same gear positions without having to move the shift lever in a pattern that would require the shift lever to end up in a position that would be difficult to reach.
Slowing the truck down. Downshifting is a little more difficult than upshifting through the gears. You must perform much of the same procedures, however, just before downshifting into the next gear you will have to touch the throttle to increase the rpm. The rpm of the lower gear is then higher than in the higher gear and to downshift successfully you must get the transmission and engine speed to match. Remember to turn the selector knob down to the low range before attempting to change gear.
Tips
Shifting gears correctly takes patience and practice, but don’t get upset if you have trouble getting it right as many experienced truck drivers still grind a gear from time to time.
Warnings
Operating an 18-wheeler or any large truck equipped with a 10-speed transmission requires training, practice and repetition. Be especially careful when operating a large truck in hilly areas, as missing a gear can lead to an accident. Also be careful when driving in adverse or winter conditions.